Manhole assemblies

ABSTRACT

A preformed manhole base member comprises a bottom and integral side members. The bottom has a main outlet channel extending to an outlet orifice in one side member. The bottom and at least one other of the side members have locating means such as grooved portions for receiving cooperating locating means such as flanges on inflow channel bends so that correct location of an inflow bend with respect to the main outlet channel is obtained.

United States Patent [1 1 Davidson et al.

Feb. 6, 1973 MANHOLE ASSEMBLIES inventors: Alastair Ritchie Davidson; Eric Robert Percival, both of London, England Assignee: Reed International Limited, London, England Filed: Oct. 15, 1971 Appl. No: 189,668

Foreign Application Priority Data Oct. 28, I970 Great Britain ..5 1,237/70 vs. C] "137/363, 285/325 Int. Cl. ..E02d 29/00 Field of Search ..l37/363; 52/19 20, 21;

[56] References Cited UNITED STATES PATENTS 3,562,969 2/l97l Little ..l37/363 X Primary Examiner-Henry T. Klinksiek Attorney-Sommers & Young [57 ABSTRACT A preformed manhole base member comprises a bot tom and integral side members. The bottom has a main outlet channel extending to an outlet orifice in one side member. The bottom and at least one other of the side members have locating means such as grooved portions for receiving cooperating locating means such as flanges on inflow channel bends so that correct location of an inflow bend with respect to the main outlet channel is obtained.

7 Claims, 4 Drawing Figures MANHOLE ASSEMBLIES This invention relates to manhole assemblies for use in underground drainage systems. Such manhole assemblies have a main outlet channel which leads to an outlet pipe and a plurality of inflow branch channels feeding the main outlet channel and leading from branch pipes.

In order to provide a wide range of entries of straight branch pipes to the manhole it is customary to provide a range of channel bends of different angular configurations for forming the inflow branch channels so that the required unimpeded flow of liquid and entrained solids into the main channel is obtained. The use of straight branch pipes also facilitates their cleaning.

In the past it has been necessary to first form a concrete support base for the manhole and then by a time consuming and expensive process of pipe fitting, bricklaying, cement infllling and benching or haunching to build up the manhole assembly. The object of this invention is to minimize the extent of this time consuming process without detriment to the flexibility of manhole design in providing a wide range of entries for the branch pipes. 7

According to this invention there is provided a preformed manhole base member comprising a bottom and integral side members, the bottom having a main outlet channel extending to an outlet orifice in one side member, and the bottom and side members having locating means for inflow channel bends such that correct location of an inflow bend with respect to the main outlet channel is obtained.

Thus the channel bends may be provided with locating flanges, one engaging in the locating means of a side member and the other engaging in locating means at the edge of the main outlet channel.

The channel bends may be provided with edges which extends to provide a screeding edge to enable any necessary benching to be carried out simply by a screeding process.

In order to complete the manhole to the desired height a plurality of interfitting manhole sections may be provided which are disposed one above the other on the base member.

In order that the invention may be readily understood, two constructions of manhole assembly in accordance with the invention will now be described by way of example with reference to the accompanying drawings, in which:

FIG. 1 is a partly broken-away perspective view of the base member of the first construction FIG. 2 is a scrap section of the base member at the outlet orifice,

FIG. 3 is a sectional elevation of a completed manhole using the base member of FIG. 1, and

FIG. 4 is a view similar to FIG. 1 of the base member ofthe second construction.

Referring to the drawings the manhole assembly has a concrete base member 1 which is of rectangular trayshape and has bottom 2, opposite side walls, referred to hereinafter as end walls 3, and opposite side walls 4. In use the base member 1 is laid on a gravel foundation 1]. A main outlet channel 5 is formed in the bottom of the base member 1 and provides a through-flow from main inlet orifice 6 in one end wall 3 to main outlet orifice 7 in the other end wall 3. The orifices 6 and 7, as can be seen from FIG. 2, are formed as sockets for receiving spigots of inlet and outlet pipes 8 and 9 (Figure 3), a sealing ring 10 being fitted on the pipes and locating against the internal-shoulders formed in the sockets 6 and 7. The only difference between the base member 1 of FIG. I and that of FIG,. 4 is that the inlet and outlet orifices 6 and 7 are in the latter case formed separately from the base member and are slid into position down the openings in the end walls 3 so that flanges 13 at their edges locate in the slots 12 in the base member 1. The opposite side walls 4 of the base member 1 are cut away so that each can be fitted with a plurality of .channel bends to provide the requisite inflow branch channels to the main outlet channel 5.

One form of channel bend 15 and its manner of fitting to the base member 1 will now be described with particular reference to FIG. 4. The channel bend 15 is formed from moulded plastics material and has at its inlet end a socket 16 for receiving a branch pipe with interfltting sealing ring in substantially the same manner as the pipes 8 and 9 are received in the orifice 6 and 7. From the socket 16 channel 17 curves in known manner and changesfrom a curved cross-section at 18 to a substantially rectangular cross-section at 19. In order to accurately locate the channel bend 15 on the base member 1 it is provided with webs 20 and 22 which locate in groves 23 and 24 respectively in the base member 1.

After fitting of the appropriate number of channel bends in the side walls 4, the necessary infllling and benching is'carried out. To facilitate the benching the edges 25 and 26 of the channel bends 15 extend to form edges for guiding a levelling and tamping board, so that the skill required for benching is minimized by making it mainly a screeding process. Holes 28 are provided in the outwardly extending webs 29 of the channel bend for keying with the concrete during benching.

To complete the manhole a plurality of sections 30 are built up on the base member 1 as shown in FIG. 3, these interfltting through tongues 31 and groove 32.

We claim:

1. A preformed manhole base member comprising a bottom and integral side members, the bottom having a main outlet channel extending to an outlet orifice in one side member, and the bottom and at least one other of the side members having locating means for inflow channel bends such that correct location of an inflow bend with respect to the main outlet channel is obtained.

2. A manhole base member as claimed in claim 1, wherein the locating means for each channel bend comprises grooved portions which are adapted to receive flanges of the channel bend.

3. A manhole base member as claimed in claim 2, wherein said grooved portions extend along said other side member and along the edge of the main outlet channel.

4. A manhole base member as claimed in claim 1, wherein said outlet orifice comprises a separately formed socket member which is slid into position down an opening extending from the top of said one side member and which has a flange locating in a groove in the base member.

5. An assembly of a manhole base member as claimed in claim 1 and at least one separately formed channel bend locating in said locating means.

6. An assembly as claimed in claim 5, wherein said channel bend has transversely extending flanges locating in said locating means.

7. A manhole comprising a manhole base member as claimed in claim 1 and a plurality of interfitting man- 5 ,hole sections disposed one above the other on the base member. 

1. A preformed manhole base member comprising a bottom and integral side members, the bottom having a main outlet channel extending to an outlet orifice in one side member, and the bottom and at least one other of the side members having locating means for inflow channel bends such that correct location of an inflow bend with respect to the main outlet channel is obtained.
 1. A preformed manhole base member comprising a bottom and integral side members, the bottom having a main outlet channel extending to an outlet orifice in one side member, and the bottom and at least one other of the side members having locating means for inflow channel bends such that correct location of an inflow bend with respect to the main outlet channel is obtained.
 2. A manhole base member as claimed in claim 1, wherein the locating means for each channel bend comprises grooved portions which are adapted to receive flanges of the channel bend.
 3. A manhole base member as claimed in claim 2, wherein said grooved portions extend along said other side member and along the edge of the main outlet channel.
 4. A manhole base member as claimed in claim 1, wherein said outlet orifice comprises a separately formed socket member which is slid into position down an opening extending from the top of said one side member and which has a flange locating in a groove in the base member.
 5. An assembly of a manhole base member as claimed in claim 1 and at least one separately formed channel bend locating in said locating means.
 6. An assembly as claimed in claim 5, wherein said channel bend has transversely extending flanges locating in said locating means. 